This invention relates generally to nuclear medicine imaging, and more particularly, to efficiently imaging structures of interest with multiple imaging detectors having small fields of view.
In nuclear medicine (NM) imaging, the time required to acquire a scan of a patient can be long, leading to patient discomfort. Furthermore, if the patient moves, the image may be degraded and the scan may need to be repeated. In addition to the cost of the equipment, a high cost of operation may also be realized due to the time and manpower required to operate the equipment. Large size imaging detectors also have limited maneuverability due to their geometry when positioned close to a patient.
In some types of scans, such as when scanning the whole body or with large patients, the portion of the patient being imaged may require the entire field of view of a conventional large size imaging detector. However, when imaging a structure which is smaller than the field of view of the imaging detector, such as the heart, liver, kidney, or a tumor, portions of the imaging detector will acquire patient data outside of the structure of interest. Therefore, an effective sensitivity is decreased which is unrelated to collimator geometrical sensitivity, but rather refers to the opportunity lost by not collecting useful information.
Also, many types of scans require imaging from a number of axial positions around the patient. For example, conventional imaging detectors often acquire data while being rotated by a gantry around at least a portion of the patient, such as approximately 180 degrees and up to 360 degrees, to obtain sufficient data of the structure for volumetric imaging and processing. This is time consuming, which limits patient through-put, and is prone to error due to patient movement as discussed above.
Therefore, a need exists for methods and apparatus to decrease the time needed to acquire image data of smaller structures during NM imaging. Certain embodiments of the present invention are intended to meet these needs and other objectives that will become apparent from the description and drawings set forth below.